In the field of consumer products, it is desirable to be able to produce products that have an attractive and sometimes unusual appearance that will appeal to consumers. It is also desirable to produce products which have interesting taste and texture combinations that will also appeal to the consumer. This latter requirement has lead to the development of filled products in which a filling is contained in an outer casing formed from a different material.
It is known to produce food products comprising an outer casing made from a first food material which contains a filling of a second food material. A wide variety of food products are produced in this way from a range of food materials. Often, the outer casing will be made from a food material which is substantially solid at normal room temperature (20° C. to 25° C.) and pressure but which may be heated or otherwise processed to place it in a flowable, plastic or clay-like state in order that the material can be shaped. After shaping, the material is allowed to solidify so as to retain the shape and to contain the filling material. A food material of this nature will be referred to herein generally as being “solidifyable” and terms such as “solidifyable material”, “solidifyable food material” and “solidifyable confectionery material” should be construed accordingly.
A variety of food materials can be used as fillings, including solidifyable food materials. However, materials which remain in a flowable state at normal room temperature and pressure are often used as fillings. These include, but are not limited to, liquid and semi-liquid fillings, soft centres and more viscous materials that will retain their shape but which are malleable to the touch, such as gums. A food material which remains in a flowable state at room temperature will be referred to herein generally as being “flowable” and terms such as “flowable material”, “flowable food material and “flowable confectionery material” should be construed accordingly. The term ‘flowable” as used herein may include solutions, suspensions, emulsions, semi-solids, creams, gels, etc, that may not be completely liquid, within its meaning. As used herein, the term ‘liquid’ refers to substances which will readily flow or maintain fluid properties at room temperature and pressure.
Filled confectionery products are particularly popular and have been produced with casings made from a wide variety confectionery materials including, but not limited to, sugar based candies and fat-containing confectionery materials such as chocolate. Chocolate is a confectionery foodstuff usually formed from one or more components of the cocoa bean. In particular, chocolate is usually formed from solids from cocoa beans, including fats, such as cocoa butter, and a sweetener such as sugar. The taste of the chocolate is typically determined by the quantity and type of fat and sweetener present, as well as the presence of other ingredients such as flavourings. A typical commercial dark chocolate will normally comprise non-fat cocoa solids, fat, sugar and optionally an emulsifier. A typical commercial milk chocolate will normally comprise non-fat cocoa solids, fat, milk solids, sugar and optionally an emulsifier. A typical commercial white chocolate will normally comprise milk solids, cocoa butter or other fat, sugar and optionally an emulsifier.
Examples of typical materials that have been used as fillings in confectionery products include: liqueurs, honey, toffee, caramel, cream, fondants, praline, fudge, gels, confectionery emulsions, jelly, jam and the like.
Filled confectionery products have been produced in a variety of different shapes and sizes and using various methods. Typically though, confectionery products filled with a flowable confectionery material are produced by moulding, such as shell-moulding or book-moulding, or by so-called “one shot” centre-in-shell depositing.
A convenient method of manufacturing elongate products is by means of extrusion. In the known methods, a material is forced through an extrusion die in a flowable, plastic or clay-like state to produce an extrudate body having a substantially constant cross section along its length. The extrudate body is subsequent is cut into lengths and may be subjected to further processing.
One approach for producing an elongate filled chocolate confectionery product by means of extrusion is disclosed in GB 223,362. In the method described, a tubular casing of chocolate is formed by extrusion. After forming, the tube is cut into lengths and one end of each length is closed. A filling is introduced though the open end of each length before the second end is closed. The apparatus and method described GB 223, 362 is relatively complex, involving several different process steps which must be undertaken to produce the final filled product.
EP 1 166 640 A1 discloses a co-extruded confectionery product in which a fat-containing confectionery material, such as chocolate, is extruded to form a hollow or tubular form surrounding a filling of another confectionery material. However, the method disclosed is only suitable for use where the filling material does not flow when the extrudate body is cut.
Whilst extrusion is a particularly efficient means of producing elongate products, the known methods are only able to produce products with limited shapes and which have a substantially constant cross-sectional profile. Accordingly, the known extrusion methods and apparatus are not suitable for producing elongate components, whether filled or not, having complex profiles whose cross-sectional area and/or profile varies along the length of the product.
Foodstuffs in general tend to be more difficult to extrude than non-foodstuffs and especially plastics and rubbers/elastomers. Handling foodstuffs gives rise to difficulties due in part to need to ensure that they are not contaminated and also that the process itself does not adversely affect the taste and/or texture of the material. For example, whilst many non-food materials can be processed at elevated temperatures, this may not be possible with certain foodstuffs. Food materials may also have non-uniform textures and/or viscosity differences within the same product batch. In contrast, non-food materials can usually be processed prior to extrusion to ensure uniform and consistent texture and/or viscosity. These issues give rise to particular problems when attempting to extrude food materials that are not met when extruding non-food materials. Accordingly, apparatus and methods used to extrude non-food materials such as plastics or rubbers/elastomers are often not suitable for extruding food materials. Extruding chocolate is particularly problematical and is rarely carried out in practice because of its low viscosity when liquid. At elevated temperatures the cocoa butter in chocolate becomes melted and flows easily. If liquid chocolate is extruded it is generally too thin to retain the extruded shape, unlike more viscous materials.
The above problems have meant that other, less efficient, processes such as moulding have to be used where the shape of the product is not suited to manufacture using the known extrusion apparatus and methods or the extruded product has to be subjected to further shaping processes.
There is a need then for improved methods and apparatus for producing products, especially but not exclusively food and confectionery products, which overcome, or at least mitigate, some or all of the limitations of the previously known apparatus and methods.
There is a need for improved methods and apparatus for producing products by extrusion which are capable of producing products with a greater range of shapes and structures than are possible using the known methods and apparatus, especially but not exclusively for use in producing food and confectionery products.
In accordance with a first aspect of the invention, there is provided a method of manufacturing products, the method comprising extruding at least one first material through an extrusion aperture defined in a die to form an extrudate body, wherein the method comprises varying the rate of flow of at least one first material through the extrusion aperture.
The method may comprise varying the flow rate of the first material through the extrusion aperture so as to vary the profile of the extrudate body along its length.
The method may comprise extruding at least two different first materials through the extrusion aperture to form an extrudate body and varying the rate of flow of each first material through the extrusion aperture so as to vary the proportion of each first material in the extrudate body along its length. The method may comprise pulsing the flow of the at least two different first materials in order to produce an extrudate body having sections predominantly formed from each of the materials positioned along its length. The method may be carried out so that the sections are alternated or otherwise sequentially positioned along the length of the extrudate body.
The method may be carried out using apparatus defining a first material supply path for the, or each, first material along which the respective first material flows to the extrusion aperture, and the method may comprise varying the rate of flow at least one of the first materials along its supply path to the die. The apparatus may comprise a control system including a flow control mechanism for varying the rate of flow of the respective first material along the supply path to the die and the method may comprise actuating the flow control mechanism to vary the rate of flow of the respective first material. The flow control mechanism may be operative to vary the volume of the respective first material supply path.
The method may comprise periodically varying the rate of flow of the, or at least one of the, first material(s) through the extrusion aperture so as to produce an extrudate body whose cross-sectional area varies along its length. The method may comprise periodically increasing or decreasing the flow of the, or at least one of the, first material(s) through the extrusion aperture so as to produce an extrudate body having a series of bulges or regions greater cross-sectional area along its length.
The extrusion aperture may comprise an upstream portion and a downstream portion, the downstream portion having a larger minimum lateral dimension than the upstream portion, and the method may comprise extruding the first material at a flow rate at which the profile of the extrudate body is determined by the shape of the upstream portion of the extrudate aperture and periodically extruding the first material at a higher flow rate at which the first material expands to fill the downstream portion of the extrudate aperture such that the shape of the extrudate body is determined by the shape of the downstream portion. The upstream and downstream portions of the extrudate aperture may have different shapes.
The die may comprise a plurality of extrusion apertures, and the method may comprise extruding the first material though the extrusion apertures at a flow rate to produce an array of separate extrudate body strands and periodically extruding the first material at a higher flow rate at which the first material exiting each extrusion aperture expands to form interconnections between adjacent ones of the strands in the array. The apparatus may be configured and the method may be carried out so that an interconnection is formed between each strand and at least one other strand in the array when the first material is periodically extruded at the higher rate so as to produce a lattice structure when the first material solidifies. The method may comprise periodically extruding the first material at a higher flow rate such that the first material exiting the extrusion apertures coalesces to form a solid intermediate section of extrudate body interconnecting all the strands and the method may also comprise subsequently dividing the extrudate body into product lengths, each division being made through one of the intermediate sections.
The extrusion die may comprise at least one inner fluid outlet and the apparatus may comprise a second material delivery system for delivering a second material in a flowable state under pressure to the at least inner one fluid outlet for introduction into the extrudate body to form a chamber filled with the further material within the extrudate body. The method may comprise varying the rate of flow of the second material through the at least one inner fluid outlet. The method may comprise varying the rate of flow of the second material through the at least one inner fluid outlet so as to produce an extrudate body comprising alternate filled and intermediate sections, the filled sections having at least one chamber filled with the second material and the intermediate sections having no chamber filled with the second material. The apparatus may include a second material supply path for delivering the second material to the at least one inner fluid outlet and the apparatus may comprise a control system including a flow control mechanism for varying the rate of flow of the second material along the supply path and the method may comprise actuating the flow control mechanism to vary the rate of flow of the second material. The flow control mechanism may be operative to vary the volume of the second material supply path. The method may comprise actuating the flow control mechanisms for both the first and second materials at the same time. The method may comprise delivering more than one second material to various inner fluid outlets and the method may comprise varying the flow rate of at least one of the second materials. The apparatus may define a supply path for each second material and may comprise a flow control mechanism in at least one of the second material supply paths. There may be a flow control mechanism in each of the second material supply paths and the method may comprise actuating each of the flow control mechanisms to vary the flow rate of the various second materials.
The method may comprise depositing a further material on the exterior of the extrudate through at least one fluid outlet located downstream from the extrusion aperture. The method may comprise pulsing the flow of the further material through the at least one fluid outlet to deposit the further material in discreet regions on the exterior of the extrudate body. The apparatus may include a further material supply path for delivering the further material to the at least one fluid outlet and the apparatus may comprise a control system including a flow control mechanism for varying the rate of flow of the further material along the supply path and the method may comprise actuating the flow control mechanism to vary the rate of flow of the further material. The flow control mechanism may be operative to vary the volume of the further material supply path. The method may comprise delivering more than one further material to various outer fluid outlets and the method may comprise varying the flow rate of at least one of the further materials. The apparatus may define a supply path for each further material and may comprise a flow control mechanism in at least one of the further material supply paths. There may be a flow control mechanism in each of the further material supply paths and the method may comprises actuating each of the flow control mechanisms to vary the flow rate of the various further materials. The further material may be the same as the first material and the method may comprise delivering the further material through the out fluid outlets to vary the profile of the extrudate body.
The method may comprise actuating the flow control mechanisms for both the first and further materials at the same time. Where the method also comprises delivering a second material to at least one inner fluid outlet, the method may comprise actuating the flow control mechanisms for each of the first, second and further materials at the same time or in a co-orientated manner.
The method may comprise synchronising the pulsing of further material and the surging of the first material such that the further material is deposited on at least some of the bulges or regions of increased cross-sectional area of the extrudate body.
The flow control mechanism for either of the first, further or second materials may comprise a movable member at least partially located in the respective supply path and movable to vary the volume of the supply path, the arrangement being such that movement of the member in a one direction increases the volume of the supply path and that movement of movable member the opposite direction decreases the volume of the supply path, and the method may comprise periodically moving the member to vary the rate of flow of the respective material.
The apparatus may comprise a first material delivery device for causing the, or each, first material to flow along a respective first material supply path to the die, the step of varying the rate of flow of the first material through the extrusion aperture so as to vary the lateral cross-section of the extrudate body along its length may comprise operating the first material delivery device so as to cause the first material to flow along the first material supply path to the die in a pulsed flow. The method may comprise varying the output of the first material delivery device to pulse the flow. Where the first material delivery device comprises a pump, the method may comprise varying the speed of the pump to vary the rate of flow of the first material. Alternatively, the first material delivery device may comprise a reciprocal ram configured to drive the first material along the first material supply path to the die.
The method may comprise deforming the first material in the extrudate body to shape the extrudate body. The method may comprise applying pressure to the exterior of the extrudate body to deform the first material radially inwardly. The method may comprise applying a ring of pressurised fluid, such as air to the extrudate body to crimp the body. Alternatively, the method may comprise using a crimp bar to apply pressure to the exterior of the extrudate body. The extrudate body may crimped within, or at a position proximal to, the extrusion die or it may be crimped at a position spaced downstream from the extrusion die. The ring of pressurised fluid may also be used to divide the extrudate body into individual lengths. In a further alternatively, where the at least one fluid outlet is located offset from a central longitudinal axis of the die and the extrudate body, the method may comprise deforming the first material radially outwardly from a central region of the extrudate body. In this arrangement, the extruder apparatus may comprise a mechanical ram which can be selectively moved into and retracted from a central region of the extrudate body and the step of displacing the first material in the central region of the extrudate body radially outwardly may be carried out by advancing the ram axially into the central region of the extrudate body. The method may comprise reducing or stopping the flow of the second material as the extrudate body is deformed.
In accordance with a second aspect of the invention there is provided a method of manufacturing products, the method comprising extruding at least one first material through an extrusion aperture defined in a die to form an extrudate body, and depositing a further material on the exterior of the extrudate body through at least one fluid outlet located downstream of the extrusion aperture.
The method in accordance with the second aspect of the invention may comprise varying the flow rate of the further material through the at least one fluid outlet. The method in accordance with the second aspect of the invention may comprise pulsing the flow of the further material through the at least one fluid outlet to deposit the further material in discreet regions on the exterior of the extrudate body. The apparatus may include a further material supply path for delivering the further material to the at least one fluid outlet and the apparatus may comprise a control system including a flow control mechanism for varying the rate of flow of the further material along the supply path and the method may comprise actuating the flow control mechanism to vary the rate of flow of the further material. The flow control mechanism may be operative to vary the volume of the further material supply path.
The method may comprise delivering more than one further material to various outer fluid outlets and the method may comprise varying the flow rate of at least one of the further materials. The apparatus may define a supply path for each further material and may comprise a flow control mechanism in at least one of the further material supply paths. There may be a flow control mechanism in each of the further material supply paths and the method may comprises actuating each of the flow control mechanisms to vary the flow rate of the various further materials. The further material may be the same as the first material and the method may comprise delivering the further material through the out fluid outlets to vary the profile of the extrudate body.
The method according to either of the first and second aspects of the invention may comprise extruding the extrudate body on to a belt which moves in a direction generally in-line with the longitudinal axis of the die.
The method according to either of the first and second aspects of the invention may be configured to manufacture food and more particularly confectionery products.
In the method according to either of the first and second aspects of the invention, the first, second and second materials may be the same or different materials in any combination. There may be more than one, first, second or second material.
Where the method comprises extruding more than one first material and/or delivering more than one second and/or further materials, the supply path for each material may comprise a flow control mechanism. The method may comprise actuating the flow control mechanisms for any two or more of the materials at the same time.
The method according to either of the first and second aspects of the invention may be configured to produce products having an overall length in the range of 10 mm to 500 mm and more particularly in the range of 20 mm to 250 mm, although products longer than these ranges could also be produced. The method may be configured to produce products which are ball or bar shaped and in particular may be configured to produce confectionery bars, especially chocolate bars.
In accordance with a third aspect of the invention, there is provided apparatus for manufacturing products, the apparatus comprising an extrusion die defining an extrusion aperture, a first material delivery system for delivering at least one first material in a flowable state to the die extrusion aperture under pressure to produce an extrudate body, the apparatus having a control system configured to vary the rate of flow of the, or at least one of the, first material(s) through the extrusion aperture.
The arrangement is such that the apparatus can vary the rate of flow of the at least one first material whilst extrusion is in progress to produce an extrudate body whose lateral cross-section varies along its length. Alternatively, or in addition, where first material deliver system is adapted to deliver two or more first materials, the flow rates of the materials can be changed during extrusion to vary the proportion of each first material in the extrudate body along its length.
The cross-sectional area of the extrusion aperture through which the first material flows may be fixed.
The first material delivery system may define a supply path for the, or each, first material, along which the respective first material can flow to the extrusion aperture, and the control system may include a flow control mechanism in at least one of the first material supply paths upstream from the die which is operative to vary the rate of flow of the respective first material along the supply path to the die.
The first material delivery system may define a supply path for the, or each, first material along which the respective first material can flow to the extrusion aperture, and the control system may include a flow control mechanism in at least one of the first material supply paths, the flow control mechanism being operative to vary the volume of the supply path so as to vary the rate of flow of the respective first material through extrusion aperture.
The first material delivery system may be configured to deliver at least two different first materials in a flowable state to the die extrusion aperture under pressure to produce an extrudate body, the first material delivery system may define a supply path for each first material along which the respective first material can flow to the extrusion aperture, and the control system may include a flow control mechanism in each of the first material supply paths, the flow control mechanism being operative to vary the rate of flow of the respective first material along the supply path to the die. The flow control mechanisms may be operative to vary the volume of their respective supply path so as to vary the rate of flow of the respective first material through extrusion aperture.
The extrusion die may comprise at least one inner fluid outlet, and the apparatus may comprise a second material delivery system for delivering a second material in a flowable state under pressure to the at least one inner fluid outlet for introduction into the extrudate body to form a chamber filled with the second material within the extrudate body.
The second material delivery system may define a supply path along which the second material can flow to the at least one inner fluid outlet, and the control system may include a flow control mechanism in the second material supply path, the flow control mechanism being operative to vary the rate of flow of the second material along the supply path to the at least one inner fluid outlet.
The second material delivery system may be configured to deliver more than one second material to various inner fluid outlets. The apparatus may define a supply path for each second material and may comprise a flow control mechanism in at least one of the second material supply paths. There may be a flow control mechanism in each of the second material supply paths.
The control system may be configured to actuate the flow control mechanisms for the various first and second materials at the same time or in a generally co-ordinated manner.
The apparatus may comprise at least one fluid outlet for a further material located downstream from the extrusion aperture and a further material delivery system for delivering the further material in a flowable state under pressure to the at least one fluid outlet, the at least one fluid outlet being positioned radially outside the extrusion aperture and configured to direct the further material inwardly towards the longitudinal axis of the die in a region of the apparatus along which the extrudate body flows as it exits extrusion aperture. The arrangement is configured to deposit the further material on the exterior of the extrudate body through the at least one fluid outlet.
The control system may be configured to vary the flow rate of the further material through the at least one fluid outlet. This arrangement allows the further material to be pulsed so that it is deposited in discreet regions on the exterior of the extrudate body and/or for the volume of the second material deposited to be varied along the length of the extrudate body.
The further material delivery system may comprise a further material supply path for delivering the further material to the at least one fluid outlet, and the control system may comprise a flow control mechanism in the further material supply path, the flow control mechanism being operative to control the rate of flow of the further material through the at least one fluid outlet. The flow control mechanism may be operative to vary the volume of the supply path in order control the rate of flow of the further material through the at least one fluid outlet.
The further material delivery system may be configured to deliver more than one further material to various outer fluid outlets. The apparatus may define a supply path for each further material and may comprise a flow control mechanism in at least one of the further material supply paths. There may be a flow control mechanism in each of the further material supply paths.
The control system may be configured to actuate the various flow control mechanisms for first and further materials, and for the second material where present, at the same time or in a generally co-ordinated manner. The control system may be configured to synchronously actuate the various flow control mechanisms.
The control system may be configured so as to periodically increase or decrease the rate of flow of the at least one first material through the extrusion aperture to produce an extrudate body having a series of bulges or regions of increased (greater) cross-sectional area along its length and to pulse the flow of the further material through the at least one fluid outlet such that the further material is deposited on at least some of the bulges or regions of increased cross-sectional area of the extrudate body.
The flow control mechanism for any of the first, second or further materials may comprise a movable member at least partially located in the respective material supply path and movable to vary the volume of the supply path, the arrangement being such that movement of the member in one direction increases the volume of the supply path and that movement of movable member the opposite direction decreases the volume of the supply path, the control system comprising an actuator arrangement for selectively moving the member in said one or said opposite direction.
The flow control mechanism for any of the first, second or second materials may comprise a flexible element mounted in the respective supply path and biased towards one of a first and a second position, the actuator arrangement comprising a fluid actuation system for selectively deforming the element towards the other of the first and second positions against the bias force. The flexible element may be made of a resiliently deformable material and configured so that the inherent resilience of the material biases the element to said one of the first and second positions.
In one embodiment, the respective supply path comprises a conduit through which the respective material can flow, the flexible element being in the form of a tube mounted about an actuation member located within the conduit so that a flow path for the respective material is defined between the exterior surface of the tubular element and the conduit, a fluid chamber being defined between the actuation member and the tubular element, the tubular element being resiliently biased towards the actuation member, the control system including a fluid actuation system for selectively introducing a volume of fluid into the chamber to expand the tubular element radially outwardly against the bias force.
In a further embodiment the supply path comprises a conduit through which the respective material can flow, the flexible element being in the form of a tube mounted about an inner surface of the conduit so that a flow path for the respective material is defined through the tubular element, the tubular element being resiliently biased radially outwardly towards the inner surface of the conduit, a fluid chamber being defined between the conduit and the tubular element, and the control system including a fluid actuation system for selectively introducing a volume of fluid into the chamber to deform the tubular element radially inwardly.
In a still further embodiment, the apparatus comprises an inner conduit, the interior of which defines a first flow passage forming part of the supply path for one material, and an outer conduit surrounding the inner conduit in spaced relation, a second flow passage being defined between the inner and outer conduits which forms part of the supply path for another material, the control system comprising a first annular, resiliently flexible element mounted about an inner surface of the inner conduit such that the interior of the element forms a part of the first flow passage, a first fluid chamber operatively connected with the first element, and a fluid actuation system connected with the chamber for selectively introducing a volume of fluid into the first chamber to deform at least part of the first element radially inwardly from an initial resiliently biased configuration to reduce the volume of the first flow passage, the control system also comprising a second annular, resiliently flexible element mounted about an outer surface of the inner conduit such that part of the second flow passage is defined between the second element and the outer conduit, a second fluid chamber operatively connected with the second element, the fluid actuation system being connected with the second fluid chamber for selectively introducing a volume of fluid into the second chamber to deform at least part of the second element radially outwardly from an initial resiliently biased configuration to reduce the volume of the other flow passage.
The fluid actuation system may also be operative to selectively at least partially evacuate the fluid chamber of fluid.
The flexible element may a flexible membrane.
The fluid may be an incompressible fluid.
The control system may be capable of actuating each flow control mechanism independently. The control system may be configured to co-ordinate the actuation of two or more flow control mechanisms. The, or each, flow control mechanism could comprise a flow control module for mounting in the material supply path. Where the apparatus has a flow control mechanism for more than one material, the mechanisms may be provided in regions of the respective supply paths defined by means of separate (e.g. non-concentrically arranged) conduits upstream from the die.
The movable member could form part of a combined flow control mechanism for two of the materials, in which case the member is partly received in the supply path for one material and partly received in the path for the other material, the arrangement being such that movement of the member in one direction increases the volume of one of the supply paths and decreases volume of the other supply path and that movement in the opposite direction decreases the volume of said one of the supply paths and increases the volume of the other supply path.
In one such arrangement where the movable member forms part of a combined flow control mechanism for two materials, the apparatus comprises an inner conduit, the interior of which forms part of supply path for one material, and an outer conduit surrounding the inner conduit in spaced relation, a flow passage being defined between the inner and outer conduits which forms part of the supply path for the other material, the inner conduit comprising a first conduit section and an adjacent second conduit section co-axial with but separated from the first conduit section, the second conduit section having an inner diameter which is larger than the outer diameter of the first conduit section, the movable member comprising a cylindrical tubular shuttle member mounted between an outer surface of the first conduit section and an inner surface of the second conduit section for movement in an axial direction between at least a first and a second position.
In a further possible arrangement where the movable member forms part of a combined flow control mechanism for two materials, the apparatus comprises an inner conduit, the interior of which forms part of the supply path for one material and an outer conduit surrounding the inner conduit in spaced relation, a flow passage being defined between the inner and outer conduits which forms part of the supply path for the other material, the inner conduit comprising a first conduit section and an adjacent second conduit section co-axial with but separated from the first conduit section, the first and second conduit sections having opposed ends that are spaced apart in an axial direction of the inner conduit sections, the movable member comprising a tubular shuttle member mounted co-axially between the spaced ends of the first and second conduit sections for movement in an axial direction between at least a first and a second position, the shuttle member being connected with the first conduit section by a first flexible seal and connected with the second conduit section by a second flexible seal, the seals being axially expandable and compressible to accommodate said axial movement of the shuttle and the interior of the seals defining a part of the supply path for said one of the materials, one of the seals having a larger average diameter than the other of the seals such that movement of the shuttle member in a direction from the first position towards the second position acts to increase the length of said one of the seals with the larger average diameter and to reduce the length the other of the seals resulting in an overall increase in the combined interior volume of the two seals.
In either of the preceding arrangements, the actuator arrangement for selectively moving the shuttle member may comprise a first magnet physically coupled to the shuttle located inside a conduit in which the shuttle is located, a second magnet located externally of the conduit and magnetically coupled with the first magnet such that movement of the second magnet in an axial direction of the conduit results in a corresponding axial movement of the first magnet and the shuttle member, and an actuator for moving the second magnet.
The first material delivery system may comprise a first material delivery device for causing the, or each, first material to flow along its respective supply path, and the control system may be configured to operate the first material delivery device so as to vary the rate of flow of the respective first material through the extrusion aperture. The control system may be configured to vary the output of the first material delivery device to vary the rate of flow of the first material. The first material delivery device may be a pump and the control system may be configured to vary the speed of the pump to vary the rate of flow of the first material. In an alternative arrangement, the first material delivery device may comprise a ram for driving the first material along the first material supply path in a pulsed flow.
Where present, the at least one inner fluid outlet may be defined in a portion of the die which is movable relative to at least one other portion of the die and the apparatus may comprise an actuation arrangement selectively moving the at least one inner fluid outlet whilst extrusion is in progress. The die may comprise an outer die part and an inner die part mounted for rotation within the outer die part about a central longitudinal axis of the die, the inner die part defining the at least one inner fluid outlet which is radially offset relative from the longitudinal axis, the apparatus having an actuator arrangement for selectively rotating the inner part of die about the axis. The actuator arrangement may be operative to rotate the inner part of the die between two discrete rotational orientations. Alternatively, the actuator arrangement may be operative to rotate the inner part of the die continuously for a period of time.
The apparatus may comprise a mechanism for deforming the extrudate body, the control system being configured to operate the mechanism periodically so as to shape the extrudate body. The apparatus may comprise an arrangement for applying pressure to the exterior of the extrudate body to deform the body radially inwardly. The apparatus may comprise an annular nozzle for surrounding the extrudate body and a pressurised fluid supply system for directing a pressurised fluid through the nozzle to subject the exterior of the extrudate body to a ring of pressurised fluid, such as air. The annular nozzle may be positioned within or proximal to the extrusion die or it may be located at a position spaced downstream from the extrusion die. Alternatively, the apparatus may comprise a crimp bar and an actuator for selectively bring the crimp bar into contact with the extrudate body to crimp the extrudate body. In a further alternative arrangement, the apparatus may comprise a mechanism for displacing material in a central region of the extrudate body radially outwardly. The mechanism may comprise a ram selectively movable in an axial direction through the centre of the die between an advanced position, in which a head of the ram is positioned for location in a central region of the extrudate body, and a retracted position, the control system having an actuator arrangement for selectively moving the ram between the advanced an retracted positions.
The die may comprise a main body portion defining one or more apertures through which the first material flows from the first material supply path, a shroud projecting axially in a downstream direction beyond an outer (downstream) end of the main body portion, the shroud defining a the extrusion aperture into which the first material is directed to form the extrudate body. The shroud may be removably mounted to the main body portion. The die may have a nozzle arrangement located centrally of the main body portion, the nozzle arrangement defining one or more apertures that are in fluid communication with the second material flow path, the one or more apertures comprising the at least one inner fluid outlet. The maximum lateral dimension (i.e. width or diameter) of the at least one aperture in the nozzle arrangement may be less than the maximum lateral dimension (i.e. width or diameter) of the second material supply path immediately upstream of the nozzle arrangement. The shroud may extend in an axial direction of the die beyond the outer or downstream end of the nozzle arrangement. The nozzle arrangement may be removably mounted to the main body portion of the die. The main body portion of the die may comprise an aperture plate, the aperture plate defining a central aperture in fluid communication with the second material supply path and at least one further aperture spaced radially outwardly from the central aperture, the at least one further aperture being in fluid communication with the first material supply path. The nozzle arrangement may be mounted to the aperture plate, the at least one nozzle aperture being in fluid communication with the second material supply path. The nozzle arrangement may comprise or have mounted thereto a generally conical body portion the apex of which is substantially aligned with the longitudinal axis of the die at the downstream end of the body. The at least one inner fluid outlet may be located adjacent the base of the conical body portion and may be aligned to direct the second material generally radially outwardly about an outer surface conical body portion.
The apparatus may comprise a plurality of inner fluid outlets configured so as to produce a corresponding number of chambers filled with the second material when the second material is introduced into the extrudate body through the inner outlets in use. The, or each, inner fluid outlet may be defined by means of an injector forming part of an extrusion die assembly.
The extrusion aperture may comprise an upstream portion and a downstream portion, the downstream portion having a larger minimum lateral dimension than the upstream portion. The upstream and downstream portion may have different cross-sectional profiles or shapes. The upstream and downstream portions may be circular, square, triangular, rectangular, star shaped or irregular. They may be the same shape or different shapes in any combination.
The die may comprise a plurality of extrusion apertures through which the first material is extruded to form a plurality of extrudate body strands.
The apparatus may comprise a moving belt located adjacent the outlet of die onto which the extrudate body is extruded, the belt moving in a direction generally in-line with a longitudinal axis of the extrusion die.
The apparatus may comprise a mechanism for dividing the extrudate body into lengths. The mechanism for dividing the extrudate body into lengths may comprise a cutter for cutting the extrudate body. The cutter may be synchronised with the action of the control system such that movement of the cutter is timed to divide the extrudate body through a desired location. The mechanism for dividing the extrudate body into lengths may comprise a sensor arrangement for detecting the desired location in the extrudate body. The apparatus may comprise an arrangement for producing an external mark on the extrudate body at or adjacent to the die to indicate the location of the desired location and the sensor arrangement may include a sensor for detecting the external mark.
The apparatus may be configured to extrude a first material which is solidifyable. The first material delivery system may comprise an arrangement for delivering the first material to the extrusion die under pressure in a plasticised condition. The first material delivery system may comprise apparatus for tempering the first material to place it in a flowable or clay-like consistency and for delivering the tempered material to the extrusion die. The apparatus may be configured to extrude at least one first material that is a food material. The apparatus may be configured to extrude at least one first food material that is a solidifyable food material and in particular a solidifyable confectionery material. The apparatus may be configured to extrude at least one first food material that is a solidifyable fat-containing confectionery material such as chocolate. The material delivery system may be configured to deliver more than one first material to the extruder die.
In apparatus in accordance with the invention, the second material delivery system may be configured to introduce more than one second material into the extrudate body. The second material delivery system may comprise a plurality of inner fluid outlets for the second materials, at least two of the outlets being fluidly connectable with supplies of different second materials. The second material delivery system may comprise an arrangement for selectively connecting at least one of the fluid outlets with sources for any one of two or more different second materials.
The apparatus may be configured to extrude the first material in a cold extrusion process.
In accordance with a fourth aspect of the invention, there is provided apparatus for manufacturing products, the apparatus comprising an extrusion die defining an extrusion aperture, a first material delivery system for delivering at least one first material in a flowable state to the extrusion aperture under pressure to produce an extrudate body, wherein the apparatus comprises at least one fluid outlet for a further material located downstream from the extrusion aperture and a further material delivery system for delivering the further material in a flowable state under pressure to the at least one fluid outlet, the at least one fluid outlet being positioned radially outside the extrusion aperture and configured to direct the further material inwardly towards the longitudinal axis of the die in a region of the apparatus along which the extrudate body flows as it exits extrusion aperture.
The apparatus may comprise a control system including a flow control arrangement for varying the flow of the further material to the at least one fluid out. The control system may be configured to pulse the flow of the further material through the at least one fluid outlet. This arrangement allows the further material to be deposited in discreet regions on the exterior of the extrudate body or for the volume of the second material deposited to be varied along the length of the extrudate body.
The further material delivery system may comprise a further material supply path for delivering the further material to the at least one fluid outlet, and the control system may comprise a flow control mechanism in the further material supply path, the flow control mechanism being operative to control the rate of flow of the further material through the at least one fluid outlet. The flow control mechanism may be operative to vary the volume of the supply path in order control the rate of flow of the further material through the at least one fluid outlet.
The further material delivery system may be configured to deliver more than one further material to various outer fluid outlets. The apparatus may define a supply path for each further material and may comprise a flow control mechanism in at least one of the further material supply paths. There may be a flow control mechanism in each of the further material supply paths.
The apparatus is configured to deposit the further material on the exterior of the extrudate body in use.
In the apparatus according to either of the third and fourth aspects of the invention, the first, second and second materials may be the same or different materials in any combination. There may be more than one, first, second or second material.
Where the apparatus according to either of the third and fourth aspects is adapted to extrude more than one first material or deliver more than one second or further material, the apparatus may comprise a flow control mechanism for some or all of the materials and the control mechanism may be configured to actuate any two or more of the flow control mechanism at the same time or in a generally co-ordinated manner.
References to flow control mechanisms being actuated at the same time should be understood as encompassing arrangements wherein the flow control mechanisms are actuated over overlapping periods of time and do not necessarily require that actuation of the mechanisms is commenced and end at the same time, although this is possible.
The apparatus according to either of the third and fourth aspects of the invention may be configured to produce products having an overall length in the range of 10 mm to 500 mm and more particularly in the range of 20 mm to 250 mm, although products longer than these ranges could also be produced. The apparatus may be configured to produce products which are ball or bar shaped or and in particular may be configured to produce confectionery bars, especially chocolate bars.
The methods and apparatus according to the various aspects of the invention can be adapted or configured for extruding a range of materials including non-food materials such as plastics, rubber, elastomers and polymers and the like. The methods and apparatus according to the various aspects of the invention though are particularly suited for extruding food materials including:
a. Confectionery materials such as: chocolate, fudge, toffee, chewing gum, bubble gum, praline, nougat, chewy candy, hard candy, fondant, caramel;
b. Confectionery fillings such as: chocolate, praline, caramel, toffee, chewing gum, jam, jelly, syrups, cream, honey, liqueurs, fondant, fudge, gels, emulsions, yoghurt;
c. Savory foodstuffs—cheese (especially processed cheese), dough (biscuit, cake, bread dough etc), cereals (rice, wheat, maize, oats, barley etc, milled or whole), meat, fish, food pastes;
d. Chewing gum base.
The methods and apparatus according to the various aspects of the invention are especially suited for extruding food materials including: confectionery materials, cheese (especially processed cheese), dough and cereal extrusion but most especially confectionery materials and most particularly chocolate.
For the avoidance of doubt, the term “extrusion” is used herein to refer generally to the process by which a material pushed or drawn in flowable, plastic or clay-like state through a die having an extrusion aperture in order to produce an extrudate body having a cross-sectional profile which is determined at least partially by the cross sectional profile of extrusion aperture. The term “extrusion” is not intended to be limited to processes or apparatus in which the material is delivered to the die by means of a screw extruder, although this may be the case, unless expressly stated. Rather, references to “extrusion” should be understood as encompassing any suitable means for delivering the material to the die which might include a single or twin screw extruder, a pump or any other suitable means for causing the material to flow through the die unless expressly limited.